High-power ultraviolet (UV) light sources are critical for the fabrication and inspection of integrated circuits with ever-shrinking feature sizes. In particular, optical diffraction constrains the size and density of features that may be fabricated and optically inspected. Accordingly, fabrication and inspection of integrated circuits is commonly performed with UV light, which may broadly include various spectral bands such as, but not limited to, deep ultraviolet light (DUV), vacuum ultraviolet (VUV) light, or extreme ultraviolet (EUV) light.
High-power sources of UV light typically generate broadband radiation such that undesired wavelengths (e.g., out-of-band wavelengths) are filtered to provide an illumination beam having a selected range of wavelengths. However, undesired or excessive absorption of out-of-band wavelengths practically limits traditional filtering techniques. For example, conventional dielectric coating filters rely on absorption of undesired wavelengths, which may result in excessive heating, distortion, and/or damage based on the intensity of light in the out-of-band wavelengths. By way of another example, many traditional filtering techniques such as, but not limited to, spatial-selective filters or transmissivity of light through a material. However, many materials have absorption bands in UV spectral bands that limit the practical thickness and/or lifespan of transmissive optical components used in filters, again due to excessive heating or damage. Therefore, it is desirable to provide a system and method that cures the above deficiencies.